I had no idea people were rude to nurses

My brother’s girlfriend is a nurse and she was talking to me the other day about what she deals with at work and how patients and their families can be berating sometimes. She said it’s common to deal with in nursing. I had no idea! Like why would anyone be rude to a nurse??? In all my years of hospital and doctor’s visits I have not once ever been even impolite to a nurse! Is this common where you work?